I understand you are seeking for a BIOS update for the Intel® NUC6i7KYK. I regret to inform you that I still do not have notifications for new BIOS release date for the Intel® NUC6i7KYK. The website still says TBD.I recommend checking downloadcenter.intel.com for future BIOS downloads. https://downloadcenter.intel.com/product/89187/Intel-NUC-Kit-NUC6i7KYK

A BIOS (51) was released in late December that included both updated ME firmware (with fixes for INTEL-SA-00086 vulnerabilities) and updated microcode (with fixes for the SpectreB portion of INTEL-SA-00088). Unfortunately, errata in this microcode caused systems to become unstable and, in some cases, could even cause it to reboot spontaneously. As a result, Intel recalled the microcode and the NUC team correspondingly withdrew this BIOS update.

Intel has root-caused the microcode issue and is working to deliver updated microcode for all of the affected processors. For most processors, the work is complete and the microcode is being evaluated. When this is complete, the various microcodes will be released to board and system manufacturers. These board and system manufacturers will, in turn, deliver BIOS updates that include the necessary microcodes for their board's supported processors. Similarly, the board and system product groups will deliver BIOS updates for their products. They will be publishing their schedules to these web pages:

If you look at these pages today, you will see that there is little schedule information on these pages currently. As soon as the microcode clears validation, you should see these pages starting to get updates regarding delivery schedules. Check them regularly.

In those cases where the same BIOS delivered the fixes for both INTEL-SA-00086 and INTEL-SA-00088 and thus the fixes for INTEL-SA-00086 were lost when the BIOS was withdrawn, the forthcoming BIOS update will again provide the ME firmware fixes for INTEL-SA-00086.